Automotive environmental testing has conventionally consisted of engine cooling system testing and the testing of systems such as the heating, ventilation, and air conditioning systems which augment passenger comfort. The requirements of these tests led to the development of automotive environmental test facilities consisting of test chambers equipped with dynamometers, solar simulators, air flow systems, refrigeration plants, humidity/precipitation systems and other support systems. Environmental test facilities have most often been designed for one specific purpose such as the testing of low temperature starting and driveability; the testing of high-temperature, grade, load performance; or the development of vehicle exhaust system components.
More recently, automotive environmental testing has expanded to include sophisticated engine management systems, fuels (octane rating) compatibility, and European high speed performance. These test requirements have presented the need for higher speed capability, low background noise levels, and higher flow quality including uniform velocity, temperature and low turbulence. Further, due to the increased complexity and cost of these test facilities, it is desirable to combine test capabilities into a single multi-purpose test facility. However, because the desired test capabilities often conflict in terms of facility design requirements, room remains for improvement over existing facilities in the achievement of the performance goals within a reasonable cost and with an energy efficient and reliable design.
The objects of the present invention are to provide an environmental wind tunnel which can provide high speed operation, relatively low background noise level, and which achieves high flow quality while at the same time, maintaining low energy consumption and reasonable facility construction cost.